Note: If you choose "No" on the "visible email" field, your email won't be visible on the message you send, and if you choose the "Yes" option, your email will be visible on your message by everyone that visits this guestbook. To put a video, you just have to click on the video icon (2nd button on the 3rd toolbar), and on the "File/URL" field put the YouTube video address, as for example: "http://www.youtube.com/watch?v=u2NmPVg_2qM&rel=1" and choose the size according to the preview. The way it works is similar for other functions like images, links, etc.